Steel Drain

ABSTRACT

A drain provides significant advantages over the prior art. A drain fabricated without seams can be easily cleaned and does not provide sites for bacterial growth. The cone and outlet sections of the drain are formed using a spinning process to eliminate the need for welds. The cone section includes a vertical interface lip, such that the outside of the cone section is welded to the rim, eliminating a weld on the interior of the cone. The weld between the rim and the cone section can be polished to eliminate imperfections on the top of the drain. The contour of the cone section also facilitates drainage, and hence reduces bacterial growth, by maintaining a downward slope on a smooth surface. For an embodiment with a membrane flange, dual walls are used such that the membrane flange can be welded to the outer wall of the drain, preventing the welding process from damaging the smoothness of the interior drain wall.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of copending provisional application U.S. Ser. No. 60/806,803, filed Jul. 10, 2006, entitled “Steel Drain”, which is incorporated by reference herein.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates in general to drains and, more particularly, to a steel drain for use in the food industry.

2. Description of the Related Art

A significant problem in the food industry, especially in the meat, poultry and dairy industries, concerns sanitary drainage systems. In current drainage systems, bacteria will often accumulate on the drains. Wastewater typically includes organic substances, such as food particles and dead flesh. This is especially true in the food industry. A cool, wet environment, along with organic substances, provides perfect breeding grounds for bacteria. Once established, it can spread to other equipment and preparation surfaces. This can result in the food products themselves being contaminated.

Therefore, a need has arisen for a drain which avoids or prevents colonization of bacteria.

BRIEF SUMMARY OF THE INVENTION

In the present invention, a drain comprises a seamless interior funnel section formed using a metal spinning process having an interior and exterior surface, a rim and a weld between the rim and the exterior surface of the interior funnel section.

This embodiment of a drain provides significant advantages over the prior art. The seamless funnel section can be easily cleaned and does not provide sites for bacterial growth. The metal spinning process eliminates the need for welds, which cause bacterial growth sites. The weld between the rim and the exterior of the interior funnel section can be polished to eliminate imperfections on the top of the drain.

In a second embodiment of a drain, an exterior funnel section is welded to the rim and surrounds the interior funnel section. A membrane flange is welded to the exterior funnel section.

This embodiment of the invention provides significant advantages over the prior art. By welding the flange to the exterior funnel section, the welding process will not cause imperfections on the interior surface of the funnel section of the drain.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIGS. 1 a and 1 b illustrate an exploded view of a funnel drain;

FIGS. 2 a through 2 f illustrate a perspective view of a trench drain;

FIGS. 3 a through 3 b illustrates anchoring tabs used to anchor the drain to rebar within a cement floor;

FIG. 4 illustrates a long drain formed from connected trench drain segments;

FIG. 5 illustrates a perspective view of a double containment funnel drain with an attached membrane flange;

FIGS. 6 a and 6 b illustrated a cross-sectional side view and a top view of the funnel drain of claim 5;

FIG. 7 illustrates a close up cross-sectional side view of the connection between the upper rim, inner funnel and outer funnel for the funnel drain of FIG. 5;

FIG. 8 illustrates a close up cross-sectional side view of the connection of the bottom rim, inner funnel and outer funnel for the funnel drain of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is best understood in relation to FIGS. 1-8 of the drawings, like numerals being used for like elements of the various drawings.

FIGS. 1 a-b illustrate an exploded view (FIG. 1 a) and a cross-sectional side view (FIG. 1 b) of a drain 10. The drain has three main sections: a main drain section 12, a strainer section 14 and a grate section 16. The side view of FIG. 1 b shows only the main drain section 12. The main drain section 12 includes the rim 18 and the funnel section 20, which includes a cone section 20 a and an outlet section 20 b. The cone 20 a and outlet 20 b are integrally formed from a single plate of stainless steel using a metal spinning process whereby a circular metal plate is formed over a spinning mandrel, using rollers to conform the metal to the mandrel. Accordingly, the funnel section 20 is completely seamless. Accordingly, there are no weld spots, seams or other discontinuities where bacteria can accumulates on the cone 20 a or outlet 20 b.

The cone 20 a is designed to have an interface lip 21 for connection to the rim 18 while providing a smooth surface. The interface lip 21 of cone 20 a fits within the rim 18. A first weld 23 a is formed between the exterior surface of the interface lip 21 and the rim 18 and a second weld 23 b between the rim 18 and interface lip 21 is formed on the outside bottom of the interface lip 21. The inner weld point 23 a is polished, typically using hand polishing tools, to be perfectly smooth. The outer weld 23 b need not be polished since it will not come into contact with matter poured through the drain 10. The top of the rim 18 and inside surface of the funnel section 20 are then sand blasted to remove any imperfections or marks which would cause a rough spot or deep scratch where bacteria could breed. A more detailed view of the inner weld 23 a is shown in FIG. 7. The result is a perfectly smooth surface where the weld between the rim 18 and the cone 20 a is not apparent, and will not provide a breeding ground for bacteria.

In the preferred embodiment, the rim 18 is cut from a stainless steel plate using a water jet to produce a flattened ring with clean edges. In particular the upper inside edge of the rim 18 needs to be smooth.

The grate 16 and strainer 14 rest on a ridge 25 on the cone 20 a. The ridge 25 is formed to have a slight downward slope, approximately 1° to 3° to facilitate the movement of any liquid on the ridge 25. The ridge 25 of cone 20 a curves downward in a smooth transition that can be easily cleaned.

The grate 16 is produced from a stainless steel plate approximately ½ inch in thickness. The slots 24 and finger holes 26 are cut through the plate using a water jet so that all edges will be perfectly smooth. Grate 16 fits within rim 18.

The strainer 14 is produced also produced from a stainless steel plate. The strainer holes 28 are cut using a punch machine and the basket shape is produced using a spinning process. If handle 30 is provided, it is welded to to the strainer 14 and all weld spots are ground and polished to eliminate and roughness. The handle 30 may also be “T” shaped, with a single weld to the bottom of the strainer 14.

Anchor tabs (not shown) are coupled to the exterior of the drain for tying to rebar in a floor. Anchor tabs are shown in connection with another embodiment of a drain in FIGS. 3 a-b.

In operation, the grate 16 and strainer 14 can be removed for cleaning and the main drain 12 can be swabbed to remove all bacteria and organic matter. Because the cone 20 a and outlet 20 b of the funnel section 20 are integrally formed from a single sheet of metal, the main body of the drain does not have any creases, seams or other discontinuities, and swabbing is extremely effective in comprehensive removal of all bacteria and organic material.

This embodiment of a drain 10 provides significant advantages over the prior art. The seamless drain can be easily and effectively cleaned and does not provide sites for bacterial growth. The cone 20 a and outlet 20 b sections of the drain 10 are formed using a metal spinning process to eliminate the need for welds. The cone section 20 a includes a lip 21, such that the outside of the funnel section 20 is welded to the rim 18, eliminating a weld on the interior of the funnel section 20. The weld 23 a between the rim and the lip 21 can be polished to eliminate imperfections on the top of the drain. The contour of the cone section also facilitates drainage, and hence reduces bacterial growth, by maintaining a downward slope on a smooth surface.

FIGS. 2 a-f illustrate a trench drain 40. FIG. 2 a illustrates a perspective exploded view of drain 40, FIG. 2 b illustrates a side view of drain 40, FIG. 2 c illustrates a top view of drain 40 and FIGS. 2 d through 2 f illustrate top, side and bottom views of the grate. Trench drain 40 is produced from stainless steel and has a main body 42 and grate 44. Main body 42 includes a rim 46 upon which the grate 44 sits.

In the preferred embodiment, the trench drain has a sloping bottom 46, best shown in FIG. 2 b. The slope may vary as appropriate, but a slope of approximately ⅛ inch per foot. The sides and bottom of main body 42 is preferably produced from approximately 14 gauge steel sheets, welded together. Any weld seams are ground and polished. A drain outlet 48 is positioned at the end at the bottom of the slope.

The grate, shown in FIGS. 2 d-f have slots and finger holes 47 cut using a water jet for completely smooth edges. Reinforcements 49 of ¼″×1″ stainless steel flat bar are welded under the grate, with all weld marks ground and polished.

FIGS. 3 a and 3 b illustrate anchor tabs 50 used to attach the drain 40 to rebar 52.

FIG. 4 illustrates and embodiment of the trench drain 40 which has an inlet and/or outlet, such that multiple trench drains can be coupled together to form a longer trench drain. In the preferred embodiment, trench drain segments 60 have a length of approximately 20 feet or less. Each outlet 62 is coupled to an inlet 64 of a sequential drain segment 60. The initial depth of the segment 60 is dependent upon the depth of the preceding trench drain at its outlet, such that the slope continues along the length of the connected drains 60. The outlets 62 are positioned at the bottom of the drain segments 60, such that there is no standing wastewater in the drain segments 60.

The inlets 64 and outlets 62 can be coupled together by welding at the installation site or by a rubber connector 66 with clamps 68.

FIG. 5 illustrates a double containment drain 80. FIGS. 6 a and 6 b illustrate a cross-sectional side view and a top view of the drain 80. The double containment drain is similar to drain 10, but it includes double-walled cone section 82 a and weep hole/outlet section 82 b section with a space in between the walls through which liquid flows from an entry weep hole 86 to an exit weep hole 87 at the bottom of the outlet section 82 b. A flange 89 is welded to the cone section 82 a at a desired height (the entry weep holes 86 are located just above the point at which the flange 89 is welded to the cone 82 a). Two half-ring sections 90 are connected to the flange 89 with bolts 92. The purpose of the flange 89 and ring sections 90 is to couple the drain 80 to a waterproof membrane. The double containment drain 80 is typically used on a second (or higher) floor, where the membrane is provided to keep liquids from propagating to a lower floor. Any liquid will be stopped by the membrane and flow to the entry weep holes 86. The liquid will pass between the walls of the double containment drain 80 and out the exit weep holes 87.

FIG. 6 a, in connection with detailed drawings in FIGS. 7 and 8, best illustrates the construction of the double containment drain 80 (the strainer and grate are not shown in the Figures; the strainer 14 and grate 16 describe in connection with FIGS. 1 a-b could be used for this embodiment as well). Inner funnel 93 and outer funnel 94 are welded to rim 96. The inner funnel 93 is similar in construction to the funnel section 20 of drain 10 of FIG. 1. Specifically, the inner funnel 93 has cone and outlet sections formed from an integral piece of metal using a metal spinning process so that there are no seams. The outer funnel 94 can have the same profile as the inner funnel, with a slightly greater radius, typically on the order of ⅛ inch greater than the inner funnel 93. The top of the inner funnel 93 has a contoured ridge 97 with a slight slope downward from horizontal (approximately 1-3 degrees) to aid in draining liquid. The interface lip 95 is welded to rim 96 and the exposed weld 98 a is polished to make a smooth transition from rim 96 to funnel 93. The interior weld 98 b need not be polished. The outer funnel is also welded to the rim 96; weld 100 need not be polished, since it will not be exposed. A smaller rim 102 is placed between funnel sections 93 and 94 and a weld 104 secures the bottom rim 102 to the funnel sections 93 and 94. Rim 102 and weld 104 are drilled to make the exit weep holes 87. The weld 104 is polished so that the bottom wall is perfectly smooth.

Flange 89 is welded to the outer funnel 94 (this may be performed prior to welding the outer funnel section 94 to the rims 96 and 104). The height of the flange will depend upon the application. The weld between the flange 89 and the funnel 94 need not be polished, since it will not be exposed. Welding the flange 89 to funnel 94 will result in distortions to the inside of outer funnel 94. However, because of the double containment design, imperfections caused by the flange welding process will not affect the inner funnel 93. Thus, the inner funnel 93 remains perfectly smooth to inhibit bacterial growth and facilitate effective cleaning.

The inside of the drain 80 is sand blasted to remove any imperfections.

In the preferred embodiment, the rims 96 and 102 are cut from a metal plate using a water jet.

Accordingly, the present invention provides significant advantages over the prior art. First, the drain is made without seams or other roughness which may harbor bacteria. Second, a drain with a membrane flange is provided which can be fabricated without the damaging effects on the inside of the drain that can be caused by welding the flange to the drain.

Although the Detailed Description of the invention has been directed to certain exemplary embodiments, various modifications of these embodiments, as well as alternative embodiments, will be suggested to those skilled in the art. The invention encompasses any modifications or alternative embodiments that fall within the scope of the Claims. 

1. A drain comprises: a seamless interior funnel section formed in a metal spinning process having an interior and exterior surface; a rim; and a weld between the rim and the exterior surface of the interior funnel section.
 2. The drain of claim 1 wherein the interior funnel section has a vertical lip welded to the rim.
 3. The drain of claim 1 wherein the interior funnel section has a ridge for supporting a grate.
 4. The drain of claim 1 wherein the ridge has a slope of approximately one to three degrees from a horizontal plane.
 5. The drain of claim 1 wherein said interior funnel section is stainless steel.
 6. The drain of claim 1 wherein the rim is stainless steel.
 7. The drain of claim 1 wherein the weld is polished smooth.
 8. The drain of claim 1 wherein the rim, weld and interior funnel section are sandblasted.
 9. The drain of claim 1 and further comprising a grate fabricated using a water jet.
 10. The drain of claim 1 wherein the rim is fabricated using a water jet.
 11. The drain of claim 1 and further comprising an exterior funnel section welded to the rim and surrounding the interior funnel section.
 12. The drain of claim 11 and further comprising a flange welded to the exterior funnel section.
 13. The drain of claim 12 wherein the exterior funnel section has entry holes formed therein proximate the flange, such that liquid entering the entry holes passes between the interior and exterior funnel sections.
 14. The drain of claim 13 and further providing a bottom rim welded between the interior and exterior funnel sections with exit holes form therethrough to pass water received through said entry holes.
 15. A method of fabricating a drain, comprising the steps of: forming a seamless interior funnel section using a metal spinning process, the interior funnel section having an interior and exterior surface; cutting a rim from a metal plate; and welding the rim to the exterior surface of the interior funnel section.
 16. The method of claim 15 wherein the welding step comprises the step of welding the rim to a vertical lip of the interior funnel section.
 17. The method of claim 15 and further comprising the step of polishing a resulting weld between the rim and the interior funnel section.
 18. The method of claim 15 and further comprising the step of sandblasting the rim, weld and interior funnel section.
 19. The method of claim 15 and further comprising the step of cutting a grate from a plate of metal using a water jet.
 20. The method of claim 15 and further comprising the steps of: forming an exterior funnel section; and welding to the exterior funnel section to the rim such that the exterior funnel section surrounds the interior funnel section.
 21. The method of claim 20 and further comprising the step of welding a flange to the exterior funnel section.
 22. The method of claim 21 and further comprising the step of forming entry and exit holes in the exterior funnel, such that liquid entering the entry holes passes between the interior and exterior funnel sections to the exit holes. 